Internal-combustion engine



I 1,520,353 E. C. KAVANAUGH INTERNAL COMBUSTION ENGINE Filed Nov. 27, 1920 Y 2 Sheets-Sheet 1 x i J4? J2 \;Z V -5Q 3 at? h I Z4;

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ATTORNEYS i fj mvambnl Dec 23, 1924. 1,520,353

E. C. KAVANAUGH INTERNAL COMBUSTION ENGINE Filed Nov.- 27. 1920 2 Sheets-Sheet 2 VKMZZW ATTORNEYS z'lv {flNVENTORQ l Patented Dec. 23, 1924.

UNITED STATES PATENT OFFICE.

ELWIN c. KAvANAUeH, or BETHLEHEM, PENNISYLVANIA.

INTERNAL-COMBUSTION ENGINE.

Application filed November 27, 1920. Serial No. 426,778.

To all whom it may concern:

Be. it known that I, ELWIN C. KAVA- NAUGH, a citizen of the United. States, and a resident of Bethlehem, county of Northampton, State of Pennsylvania, have invented certain new and useful Improvements in Internal-Combustion Engines, of which the fo-llowingis a specification.

Some of the objects of the present invention are to provide an improved construcvarying the inlet and exhaust ports of the working cylinder; to provide means for varying the volume of the working cylinder as desired; and to provide other improvements as will hereinafter appear.

In the accompanying drawings, Fig. 1 represents a central, sectional elevation of an internal combustion engine embodying One form of the present invention; Fig. 2 represents a similar elevation taken in a plane at right angles to that of Fig. 1; Fig. 3 represents a section on line 3-3 of Fig. 1 and Fig. 4 represents one form of spacing element for varying the volume of the engine cylinder.

Referring to the drawings, one form of the present invention is shown as applied to an engine of the two cycle type having a base 10 arranged to form crank shaft bearings 11 and to form a support for a cylinder casing 12,- and which may be used in conjunction with a lower portion 13. The upper portion thereof is provided with openings 14, or may be of other skeleton construction to permit free circulation of air through the interior of the base and its parts.

For driving the main shaft 15, crank arms 16 are provided and connected by a crank pin 17 to a piston rod or pitman 20, which is secured at its opposite end to a wristpin 21 journalled in ahub bearing 22 forming an integral part of a member 23 which is rigidly fastened to a part of the piston 24.

In the present construction the cylinder casing 12 is arranged to provide a working chamber 25 atone end and a chamber 26,

at the other end, the latter in one position of the piston forming an intake chamber, and in another position of the piston formlng a cooling chamber, and being formed between a preferably diametrically enlarged portion 27 of the cylinder casi 12 and an internal offset open ended sleeve 28, the construction being such that the intake chamber 26 is of annular form and of suflicient volume for the purpose intended. One portion of the intake chamber 26 is arranged to be brought into communication with a mixture intake 30' passing through the wall of the casing 12, ,while the opposite portion of the chamber 26 is in communication with an outlet port 31 through the casing portion 27. In the present construction the intake 30 is located adjacent the upper end of the chamber 26 and the outlet 31 is adjacent the lower end-of the chamber 26 and upon the opposite side. An opening 32 or openings are arranged in communication i with the upper end of the intake chamber 26 for relief or cooling purposes as will later appear.

For the purpose of controlling the ad mission of the explosive mixture to the chamber 26 and thereafter effecting its r nioval, the sleeve 28 is externally spaced from the inner wall of the working chamher 25 to interfit with a tubular extension 33 of the piston 24, this extension 33 passing within the chamber 26 and terminating in an outwardly flared plunger part 34, arranged for close sliding fit with the wall of the said chamber 26. Suitable packing rings 35 are provided to prevent leakage between the piston extension 33 and the fixed parts relativeto which it slides. The piston extension 33 is provided with a port 36'arranged to register with the intake 30 at a pre etermined point in the stroke of the piston 24 to thereby establish communication between the intake 30 and a channel 37 which leads to the intake chamber 26.

Preferably the channel 37 is formed in a boss 38' of the fixed'sleeve 28 and has a length suflicient to'bring the'outlet of the channel 37 below the end of the piston extension 33 when the latter is in a position to bring the port 36 into registering posillO tion. Thus at or near the end of the upstroke of the piston 24 the chamber 26 is thrown into communication with the mixture intake 30 and the vacuum in said chamber 26 causes a charge to be drawntherein. .Upon the down stroke of the piston 24 the plunger part 34 ejects the charge by way of the open outlet port 31.

In order to deliver this charge to the working chamber 25 of the cylinder the outlet port 31 communicates with a passage which is formed by a suitably shaped cover plate 41 bolted or otherwise secured to the cylinder casing 12. passage 40 communicates with the working chamber 25 by way of a port 42 through the casing 12, the opening and closing of which is accomplished by the piston 24. A screen 43 or any other suitable means may be placed across the passage 40 to prevent backfiring. An exhaust port 44 forms a communication between the chamber 25 and an exhaust pipe 45, this port 44 being substantially in the same horizontal plane as the port 42 and also opened and closed by the piston 24. The two ports 42 and 44 are properly proportioned to perform their respective functions in the most eflicient manner, the latter, however, being preferably the larger to pass the spent ases quickly and to prevent after-burning.

As a means for effectively carrying out the scavenging of the working cylinder,

' the piston 24 has its outer face formed with an outwardly projecting abutment 46 from which, on one side the piston end I curves toward the inlet port 42, and on the other inclines toward the exhaust port. By this construction the incoming charge sweeps upwardly in close proximity to the cylinder wall on one side, thus driving the burnt gases down along the other side to the exhaust port 44 and effectually cleansing the cylinder. 25 is provided with any suitable type of spark plug-47 for firing the' charge.

For the purpose of proportioning the quantity of the mixture charges in accordance with variations in load, or speed conditions, or grade of fuel, the inlet port 42 is arranged to be controlled by a valve 50, here shown as of the rock type, having a cut away portion to permit unrestricted communication between the passage 40 and working chamber 25 under general working conditions. This valve 50 is provided with an axially projecting stem 51 whereby the valve 50 may be turned as desired to diminish the size of the port 42 according to requirements. In the present instance the stem 51 is actuated by an arm 52 rigid therewith and pivoted to a link 53 arranged to be operated by a handle 54 or any other suitable means. The exhaust This The working chamber port 44 may be similarly regulated as to its opening by a valve 55, also, preferably of the rock type, giving a normal full opening to the port 44 and arranged to be actuated by an axially disposed stem 56 which is fast to an arm 57 connected to the link 53. In this manner both the inlet port 42 and the exhaust port 44 can be regulated as to opening, it being understood that the regulation is predetermined, the two valves restricting the respective port openings proportionately.

As a means for varying the volume of the working cylinder 25 to meet varying conditions, rings 60 having a diameter equal to the diameter of the cylinder 25 but varying in thickness may be employed. Each of these rings 60 is arranged to fit between the cylinder head 61 and the end of the cylinder 12, so that by removing the head 61, inserting the required size of ring 60 and again clamping the head 61 in place, the volume of the working chamber25 has been changed in the desired manner.

In describing the operation of the engine it will be assumed that the cycle starts from the position of the parts in Fig. 1. The new charge has just replaced the spent charge and as the piston 24 makes its up stroke the charge is compressed in the workingchamber 25 and fired at the proper time.

- As the piston 24=reaches the end of the up stroke the port 36 registers with the intake port 30 and the negative pressure in the annular chamber 26 causes a charge of gas mixtureto be drawn in. After firin has taken place the working or down stro e of the engine, in addition to driving the main shaft, expels the charge by way of port 31, passage 40, and port 42 to the working chamber 25. sweeps out the residue of the last charge, scavenges the cylinder. and is then compressed by the. return stroke of the piston. The cycle then repeats and continues as long as the engine is in operation.

In connection with the connection between the piston 24 and the pitman 20 it should be noted that this is arranged to expose the bearings of these parts on all sides to the air, which has free access thereto by way of the open base or through opening or openings 32 and maintains these parts cool as well as internally cooling the piston sleeve and its associated parts.

Although only a single form is shown in which this invention may be embodied, it is to be understood that the invention is not limited to any specific construction, but' This fresh entering charge casing forming a working chamber at one end, an open ended sleeve projecting within the other end of said casing to .form therewith anintake chamber, an intake port arranged to communicate with said intake chamber, an outlet port communicating with said intake chamber, means forming a communication between said outlet port and said working chamber, and a piston in said working chamber arranged to open said intake port at substantially the end of the non-working stroke of said piston.

2. In an internal combustion engine, a casing forming a working chamber at one end, an open ended sleeve projecting within the other end of said casing to form therewith an intake chamber, an intake port arranged to communicate with said intake chamber, an outlet port communicating with said intake chamber, means forming. a communication between said outlet port and said working chamber, and a piston in said working chamber arranged to close said intake port at substantially the beginning of the working stroke of said piston.

3. In an internal combustion engine, a

casing forming'a working chamber at one end, an open ended sleeve projecting with in the other end of said casing to form therewith an intake chamber, an intake port arranged to communicate with said intake chamber atthe working chamber end thereof, an outlet port communicating with said intake chamber at the other end, and a piston arranged to control said intake port.

4. In an internal combustion engine, a casing forming ,a working chamber at one end, an open ended sleeve projecting within the other end of said casing to form therewith an intake chamber, an intake port arranged to communicate with said intake chamber at the working chamber end thereof, an outlet port communicating with said intake chamber at the other end, and a piston arranged to open said intake port on the non-working stroke.

5. In an internal combustion. engine, a casing forming a working chamber at one end, an internal open ended sleeve arranged to form an intake chamber with the other end of said casing, said sleeve having a passage formed therein to communicate with said intake chamber at one end, an intake port through said casing to register with. the other end of said passage, a conduit forming a communication between said in take chamber and said working chamber, a piston, and means carried by said piston for controlling communication between said intake port, said passage, and said intake chamber.

6. In an internal combustion engine, a casing forming a working chamber at one end, an internal open ended sleeve arranged to form an intake chamber with the other endof said casing, said sleeve having a passage formed therein 'to communicate with said intake chamber at one end, an intake port, a piston, and an extension on said piston telescoping with said sleeveand arranged to establish communication between said mtake wit and said intake chamber by way 0 said passage.

7. In an internal combustion engine, a"

means for varying'the size of said inlet port,

8. In an internal combustion engine, a casing forming a working chamber at one end, an open ended sleeve projecting within the other end of said casing to form therewith an intake chamber, an inlet port and an exhaust port for said working chamber, a piston, means controlled by said piston for admitting an explosive mixture to said intake chamber, means also controlled by said piston for delivering said explosive 'mixture to said working chamber, and means for varying the size of said exhaust port.

9. In an internal combustion engine, a casing forming a working chamberat one end, an open ended sleeve projecting within the other end of said casing to form therewith an intake chamber, an inlet port and an exhaust port for said working chamber, a piston, means controlled by said piston for admitting an explosive mixture to said intake chamber, means also controlled by said piston for delivering said explosive mixture to said working chamber, and means for simultaneously varying the size of both of said ports. 1

10. In an internal combustion engine, a casing forming a working chamber at one end, an open ended sleeve projecting within the otherend of said casing to form therewith an intake chamber, an intake port, means including a piston for establishing communication between said intake port and said intake chamber at the end of the non-working stroke, and a normally open conduit between one end of said -'intake chamber and said working chamber.

11. In an internal combustion engine, a casing forming a working chamber at one end, an open ended sleeve projecting within the other end of said casing to form therewith an intake chamber, an intake port, means including1 a piston and a sleeve having a passage t erein forestablishing communication between said intake port and said intake chamber, and a normally open conduit between one end of said intake chamber and said Working chamber.

12. In an internal combustion engine, a casing forming a Working chamber. at one end, an open ended sleeve projecting Within the other end of said casing to form therewith an intake chamber, an intake port ar- 10 ranged to communicate with said intake chamber, means forming a communication between said intake chamber and said Working chamber, and a piston arranged to close said intake port substantially at the beginning of the working stroke and maintain said port closed during the Working stroke. Signed at Bethlehem, in the county of Northampton, and. State of Pennsylvania, this 11th day of November, 1920.

ELWIN C. KAVANAUGH.. 

